let promises = Promise.resolve("后盾人");
//每次then都返回一个new promise，就会形成队列
promises = promises.then((value) => {
  console.log(value);
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      console.log(1);
      resolve();
    }, 1000);
  });
});
promises = promises.then((value) => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      console.log(2);
      resolve();
    }, 1000);
  });
});
promises = promises.then((value) => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      console.log(3);
      resolve();
    }, 1000);
  });
});
